Arch Linux

Description: The grub-install man page includes the following line for the "--target" option:
"install GRUB for TARGET platform [default=%s]; available targets: %s"
where the first %s is replaced with the default value, and the second by the list of available values.

The default value of this parameter depends on both build-time and run-time checks, defined in the function "get_default_platform" in util/grub-install.c

In particular, when built for x86 systems, it delegates to grub_install_get_default_x86_platform in grub-core/osdep/linux/platform.c , which checks if the system it's running on is EFI based or not and returns different results on this basis. This is pulled into the help output, which is pulled into the man page by help2man, which means the man page will have different contents depending on the system used to build it. Additionally, if grub is then installed on a system with different configuration, the man page will actually be incorrect about the defaults for grub-install.

Steps to reproduce:
1) Acquire an EFI based system (or possibly one using ieee-1275 Open Firmware
2) Install package "archlinux-repro" via pacman
3) Download grub-2:2.04-8-x86_64.pkg.tar.zst from an archive or mirror
4) Run "repro /path/to/downloaded/grub-2:2.04-8-x86_64.pkg.tar.zst"
5) (Optional) Run "diffoscope ./build/grub-2:2.04-8-x86_64.pkg.tar.zst /path/to/downloaded/grub-2:2.04-8-x86_64.pkg.tar.zst" to see differences
6) (Optional) Run "grub-install --help" and "man grub-install" and observe that they list different defaults for "--target", the first will show "default=x86_64-efi" and the second will show "default=i386-pc"